In the following paper Opisthobranchs are described from Australia generally. Notes had been made on these either at the time of collecting, or when they were brought alive to the Museum, so that observations on them and records of their correct colours would be available for future reference. In this way, many useful notes on other new or uncommon species have accumulated, and are ready to be converted into more complete descriptions when the preserved animals are thoroughly examined.
If little work has been done on the Australian Nudibranchs, still less has been done on the Opisthobranchs generally, though the coast of Australia should be rich in this order, particularly in the northern regions. I therefore think it will serve a better purpose to publish what material I have ready for publication in small papers than to accumulate it for a larger paper.
My thanks are due to those who are mentioned in the text for their kindness in collecting and carefully preserving specimens for me.